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Old 04-15-2015, 08:33 PM
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Electronic M Electronic M is offline
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Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 15,437
Quote:
Originally Posted by tvcollector View Post
I'm getting -72 DC volts at pin 7.. Sams calls for -120.. Someone must have replaced or removed the Horz osc, one or two of the solder pads have been burnt off and jumpered from the horz osc.. Sams and the printed boards are incorrect from each other...
The osc. signal is definitely not properly reaching the HO grid. Test and or replace all suspect parts in the osc, and all parts from it leading to the grid of the HO Tube.

A near 50% positive increase in the HO grid voltage is the main cause of the problem. The HO tube is going to conduct way too much current until it's grid drive signal is made right....I recommend removing the top lead and disconnecting the screen grid (not the control grid) lead from the socket of the H output tube. until you can get the grid voltage back in the ballpark.
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